Changes in the living environment, such as the Westernization of the diet, the home environment, lack of exercise, high stress levels, and so forth, have in recent years led to a trend of annual increases in the number of individuals suffering from and at high risk for national diseases, i.e., allergic diseases and metabolic syndrome.
The number of patients with allergic diseases and particularly hay fever and atopic dermatitis is increasing annually, and therapeutic and preventive measures are also required from the standpoint of patient quality of life (QOL). The group I allergic diseases, such as hay fever and atopic dermatitis, start with the recognition of a substance introduced into the body as an allergen and subsequent induction of the production of IgE antibody. When the allergen is then reintroduced, the allergen binds to IgE antibodies that have become bound to receptor molecules on mast cells and granulocytes, which results in excessive release of chemical mediators, such as histamine and leukotriene, from the mast cells and granulocytes and causes allergy symptoms such as asthma, dermatitis, nasal discharge, and so forth.
Currently, there have been developed antiallergic agents that relieve allergy symptoms by inhibiting the release of these chemical mediators, antihistamine agents that inhibit the transmission of information by the chemical mediators to the peripheral nerves, and steroidal agents that reduce inflammation; however, side effects are seen with these drugs and at the present time there are also safety issues with regard to their methods of use and their long-term use.
In addition, the number of patients with so-called lifestyle diseases, i.e., diabetes, hyperlipidemia, hypertension, and so forth, is also following an upward course. These diseases are believed to be caused by an accumulation of undesirable lifestyles, e.g., unbalanced diet, lack of exercise, alcohol consumption, and smoking, and so forth. While dietary therapy and exercise therapy are regarded as effective methods for the treatment and prevention of these diseases, it is difficult to rigorously sustain these therapies, and therapeutic and preventive methods are thus required that are not accompanied by severe mental and physical demands.
On the other hand, fermented food products that employ lactic acid bacteria include fermented food products that have health effects, e.g., intestinal regulatory actions, preventive effects with respect to lifestyle diseases, immunostimulatory effects, and so forth, and these products have been receiving attention. For example, in the case of yogurt, the lactic acid bacteria cells used for fermentation and the milk peptides in the fermented milk are reported to exhibit health functions as described above. At the present time attention is being paid, for example, to the antiallergic functions (for example, Patent References 1 and 2: Japanese Patent Application Laid-open No. H9-2959 and Japanese Patent No. 3585487), the anti-hyperlipidemic functions (Patent Reference 3: Japanese Patent Application Laid-open No. H10-298083), and the anti-diabetic functions (Patent Reference 4: Japanese Patent Application Laid-open No. H10-7577) of lactic acid bacteria and fermented food products. Among these, the Lactobacillus paracasei strain KW3110 (FERM BP-08634) described in Patent Reference 2 is reported to have a particularly high antiallergic action, but it still cannot be said that this is satisfactory. In addition, lactic acid bacteria individually having multiple functions at a high level are not well known.
Patent Reference 1: Japanese Patent Application Laid-open No. H9-2959
Patent Reference 2: Japanese Patent No. 3585487
Patent Reference 3: Japanese Patent Application Laid-open No. H10-298083
Patent Reference 4: Japanese Patent Application Laid-open No. H10-7577